> On the other hand, I don't see the point of using Atom for returning
collections. It was written as a format for feeds not a collection format.

Hi Bill,

So just to clarify, the original idea wasn't so much to wrap the VMs
collection in an Atom feed, but rather to use a feed to allow clients,
having previously executed a query over the VM collection, to receive
lightweight notifications of changes to the set of known VMs and their
status. For example a new VM appears, the status of another VM changes,
a third VM goes away, etc.

This would allow clients to update their previous result set, without
necessarily re-issueing the original query. It would of course depend on
the feed being filtered on the client-side according the original query
constraints.

To ensure that only genuinely fresh updates were received, idea was to
use delta encoding with the cleint setting the "A-IM: feed" header so
that it recieves only those entries that were updated later than the
If-Modified-Since header (set to the timestamp of the original query or
the last GET on the Atom feed, which-ever is the later). It was an open
question whether the RESTeasy Atom provider supported delta encoding in
this way. I'll need to check this out, unless you know off the top of
your head?

Resteasy's atom support is just a bunch of JAXB classes. The Content
class has a bit more logic in that it allows you to extract
application-specific JAXB content. That's it.

If a content handler was written for this delta type you're talking
about, then I could probably easily modify the lightweight Atom classes
in RESTEasy to extract the object you're interested in.